Multi-color ribbon and mechanism

ABSTRACT

A two color printing ribbon mechanism for adding, calculating or the like machines in which the ribbon has two differently colored sections arranged end-to-end. Normally, a first and most frequently used ribbon section is held in contact with an inking device and the second less frequently used ribbon section is located at the printing line. During a cycle of the machine in which the first section is to be used for imprinting, and prior to the printing operation, the ribbon is moved endwise to locate the first section at the printing line and to move the second section into contact with a second and appropriately colored inking device. During a cycle in which the second section is to be used for imprinting, the ribbon moving mechanism is merely disabled, leaving the second ribbon section at the printing line during the printing operation.

ilnited' States Patent 1191 Clary I 1451 Aug. 28, 1973 MUL'll-COLOR RIBBON AND MECHANISM 2,724,332 11/1955 Schlessigeret a1. 101/336 01 336 X [75] Inventor: John G. Clary, Pasadena, Calif. 1971 Clay 1 l [73] Assignee: Addmaster Corporation, San Primary Examiner-Ernest T. Wright, Jr.

Gabriel, Calif. Attorney-Fred N. Schwend [22] Filed: May 6, 1971 [21] A l N 140872 [57] ABSTRACT pp A two color printing ribbon mechanism for adding, calculating or the like machines in which the ribbon has [52] US. Cl 101/336, 197/151, 197/171 two differently colored sections arranged end-to-end. [51] Int. Cl B4lk 1/48 Normally, a first and most frequently used ribbon sec- [58] Field of Search 197/ 151, 171, 172, tion is held in contact with an inking device and the 197/ l 101/336 second less frequently used ribbon section is located at the printing line. During a cycle of the machine in [56] References Cited which the first section is to be used for imprinting, and UNITED STATES PATENTS prior to the printing operation, the ribbon is moved 3,412,839 11/1968 Smith et al.....' 197/151 x endwise the first 9 9" prinfing 2,761,539 9/1956 puma et 197/171 and to move the second section into contact with a sec- 3,146,708 9/1964 Kuhne 107/171 x nd and pp p y colored inking device- During 8 2,329,129 9/1943 Mehan 197/151 cycle in which the second section is to be used for im- 880,375 2/1908 Felbel 197/172 X printing, the ribbon moving mechanism is merely disl,253,434 1913 P l97/171 abled, leaving the second ribbon section at the printing 1,377,532 5/1921 Weld 197/171 line during the priming operation I 1,846,498 2/1932 Stephenson 197/171 2,273,513 2/1942 Carlton 101/336 X 8 Claims, 10 Drawing Figures r" 4' 5 I A? F r" [a b; 72 4 i 5 47 72 $1.3 2 1 8 4 i 88 7.3 1 x 552 E ,5.5 E

e" 1 =85 s": 1. ("I L. 1 1 J J1 5 2: If 5 1 I L 1 I SE i E Q 1 1 F 2 ,2 a E 1:11 2; s 8/ A f g b 7a M11, 11-. 77 I T g 80 A \p l t W ,1, ms 27 a j /9 /7 PATENTED AUG 2 8 i975 SHEEI 1 0F 3 INVENTOR. JOHN G CLAQY PAIENIEBmsza ms 3. 754 504 sum 2 or 3 JOHN G. CAAQY BY Z PATENIEDmszs ms SNEEI' 3 [IF 3 MULTI-COLOR RIBBON AND MECHANISM BACKGROUND OF THE INVENTION BRIEF DESCRIPTION OF THE DRAWING I FIG. 1 is a sectional view through the printing mechanism of an adding-listing machine embodying one form of the present invention.

FIG. 2 is a transverse sectional view taken substan- 'tially along the line 22 of FIG. 1.

Heretofore, however, such mechanisms generally employed a relatively long printing ribbon having two differently colored strips extending side-by-side along the length of the ribbon. The ribbon was fed from one ribbon spool to another and then back. A ribbon vibrator or shifting mechanism was provided to shift the ribbon, or that part thereof which extends along the printing line, laterally to position. one or the other of the differently inked strips in position to imprint.

Although such prior multi-colored mechanisms are generally satisfactory, they require relatively complicated ribbon feeding and positioning mechanisms. Also, since such printing ribbons, and therefore the laterally spaced colored strips, are normally quite narrow, that portion of the ribbon located on the printing line may not always be properly, positioned laterally and consequently part of the characters being printed may sometimes beprinted in an unwanted color. Further, re-inking' devices for such multi-color ribbons have never proved satisfactory.

SUMMARY OF THE INVENTION A principle object of the present invention is to obviate the necessity for a long printing ribbon having two differently colored ink strips therealong for printing in either two colors.

Another object is to provide a simple. yet reliable reinking device for reinking two separate and differently colored sections of the printing ribbon during use.

Another object is to provide a very simple andinexpensive two color printing mechanism for machines of the above type.

This invention comprises an elongate printing ribbon having two differently colored sections arranged endto-end. Normally, a first colored section is held-in con-, tact with areinking device and the second colored section islocated. inimprinting. position at the printing line. During an ensuingmachine cycle in which the. first ribbon section is to be used for printing, and before the printing operation, the ribbon is shifted endwise'to po- If a machine operationrequiring imprinting by the second section is initiated, the ribbon' is merely not shifted and therefore the second section already stands on the printing line in position to-print.

FIG. 2a is a sectional plan view of the ribbon inking spool and magazine, and is taken below the level shown in FIG. 2.

FIG. 3 is a sectional view taken substantially along the line 33 of FIG. 1, illustrating the printing ribbon actuating slides.

FIG. 4 is a sectional plan view taken along the line 44 of FIG. 3.

FIG. 5 is a sectional view taken along the line 5-5 of FIG. 3.

FIG. 6 is a sectional side view of the drive mechanism -for the printer sectors and ribbon actuating slides.

FIG. 7 is a view similar to FIG. 2 but illustrating a modified form of the invention.

FIG. 8 is a sectional view taken along the line 8-8 of FIG. 7.

FIG. 9 is a sectional view taken substantially along the line 9-9 of FIG. 7. I

DESCRIPTION OF PREFERRED EMBODIMENT The present invention is disclosed as embodied in the well known Addmaster adding-listing machine. However, for the sake of brevity, only those parts of the machine which comprise the ribbon mechanism and those parts which cooperate with such mechanism are disclosed in detail. Reference may be had to the following U.S. patents for disclosure of details of the machine not specifically shown herein:

R. E. Busch U.S. Pat. No. 3,113,719 issued on Dec. 10, 1963; H. L. Clary et al., U.S. Pat. No. 3,132,582 issued on May 12, 1964; B. F. Kuhne U.S. Pat. No. 3,146,708 issued on Sept. I, 1964.

Although the invention is disclosed as embodied in an adding-listing machine, it should be understood it could equally well be embodied in other forms of printing machines.

Referring to the drawing, a pin carriage 11 containing a field of set-table stop pins 12 is shiftable laterally of the machine and for this purpose it is slideably mounted at its lower end on a stationary rod 13 and has an extension 14 at its upper end which is slidable along a slot 15 fonned in a channel member 16 comprising part of the machine framework. I I Amounts are set into the pin carriage 11 in a well known manner under control'of depressible input keys, not shown, to move corresponding'stop pins 12 endwise to set positions. As each stop pin 12 is' set the pin carriage l l is stepped along the-rod 13 into cooperative relation with a series of printing sectors 17 so that each set stop pin 12 forms-an arresting abutment in the path' of a shoulder. 18 formed on the aligned sector 17.

The sectors 17 are independently mounted for rotation on a shaft 20 rotatably supported in bearings 19,

, FIG. 2, carried by spaced side frames 21 and 22forming part of the framework of the machine.

During each machine cycle the sectors 17 are yieldably driven'clockwise from their illustrated home positions shown in FIG. 1 by a bail rod 23 which extends through openings 24 in the various sectors 17 and is normally engageable by a detent shoulder 25 formed on a yieldable tail 26 integral with each sector 17 and extending into the respective opening 24.

The bail rod 23 is mounted at its opposite ends on arms 27, FIGS. 2 and 6, fixed on the shaft 20. A sector 29, also fixed on the shaft 20, meshes with a second sector 28 in the form of a bail pivotally supported at 30 and carrying a cam follower roller 31 which follows a cam groove 32 formed in a cam 33 attached to a cyclically operable main drive shaft 34.

As disclosed in detail in said H. L. Clary el al., U.S. Pat. No. 3,132,582, during each cycle of the machine initiated by depression of suitable control keys, such as a minus total key 351, FIG. 9, the main shaft 34' is caused to rotate one complete revolution in a clockwise direction, thereby causing the cam 33 to oscillate the sectors 28 and 29. Thus, the bail rod 23 yieldably advances the various printing sectors 17 clockwise until they are arrested by aligned set stop pins 12, at which time the tails 26 will yield, permitting the bail rod 23 to continue to the limit of its excursion.

Following a printing operation, which occurs at a mid-point in each machine cycle, the bail rod 23 is returned counterclockwise by the cam 33 to likewise return the various printing sectors 17 to their home positions.

The sectors 17 cooperate with a printing mechanism generally indicated at 35 to print amounts onto a paper strip indicated by the dot-dash line 36. For this purpose, each sector 17 carries a font of type characters 37 on its periphery ranging in value from to 9, the character 0 being located clockwisemost relative to the rest of the characters 37.

The paper strip 36 is led over a feed roll 38, through a guide chute formed by spaced guide members 40 and 41, past a printing line P or station located between the sectors 17 and respective ones of a row of print hammers 42. From the printing station P the strip 36 is guided upwardly between an upstanding wall 43 of the guide member 40 and a transparent tear-off bar 44.

The hammers 42 are guided for endwise movement at their upper ends in guide slots 39 formed by a frame brace 45 and their lower ends have slots 46 guided over a stationary guide bar 47. Leaf spring elements 48 are attached at 50 to the brace 45 and individually urge the hammers 42 downwardly toward printing contact with the paper strip 36 but are normally restrained from doing so by a cam 51 carried by a shaft 52. The cam 51 normally acts through a cam follower bail 53 pivoted at 54 to hold the spring elements 48 and hammers 42 in their upper illustrated positions. The cam shaft 52 is suitably entrained, through gearing shown in said H. L. Clary et al., U.S. Pat. No. 3,132,582, with the main drive shaft 34 so that during the printing phase, which occurs during a mid portion of a cycle, the cam 51 drops away from the bail 53, permitting the spring elements 48 to impel the hammers 42 downwardly to cause an imprint of aligned ones of type characters 37 onto the paper strip 36 through an inked printing ribbon 55.

An accumulator generally indicated at 56 and including a plurality of ordinally arranged accumulator gears 57 is normally maintained out of cooperative relation with the sectors 17. The accumulator 56 is mounted on an accumulator shaft 58, FIGS. 1 and 5, which is slideably transversely, at opposite ends, in inclined slots, Le. 60, formed in the side frames 21 and 22. The details of the accumulator 56 are disclosed in said R. E. Busch U.S. Pat. No. 3,113,719.

During a digitizing phase of a machine cycle, which occurs either before or after the printing phase depending on the type of operation, a camming bail 62, pivotally supported on a rod 63 and having camming slots 64 enbracing rollers 65 on the ends of the accumulator shaft 58, is rocked counterclockwise by suitable camming means carried by the shaft 34. Such camming means is disclosed in said R. E. Busch U.S. Pat. No. 3,113,719. The bail 62 acts to cam the accumulator gears 57 into mesh with gear teeth 156 formed on the sectors 17.

During an item entry cycle, as when adding or subtracting amounts, and when the sectors 17 are rocked by the bail rod 23 as described heretofore, the accum ulator gears 57 are advanced amounts dependent upon the advance of the sectors 17 to register such amounts at the printing line P. During a totaling or subtotaling operation, the bail 62 is also rocked counterclockwise to mesh the accumulator gears 57 with the sectors 17 so that during subsequent advancement of the sectors 17 the accumulator gears 57 are returned to zero registration where they are arrested, leaving the sectors 17 in positions registering the total or subtotal amounts at the printing line P.

According to the present invention, the printing ribbon 55 is attached at one end to a hook 71 secured to the side frame 22 and passes around a roller 72, an inking spool 73, a guide roller 74, between the hammers 42 and sectors 17, and onto a rotatable inking spool 75 to which it is attached at 76. The spool 75 is somewhat similar to that shown in the aforementioned Kuhne U.S. Pat. No. 3,146,708 and comprises an ink saturated hub or core 77 of felt or the like. The spool 75 is rotatably mounted at 78 within a magazine or container 80 which is removably secured to a bracket 81 extending from the side frame 21, there being an opening 79 in the side of the magazine 80 through which the ribbon 55 passes. A tension spring 82 is secured at one end to a stud 83 on the spool 75. The spring 82 passes around a suitable arcuate flange 175 on the spool 75 and is secured at its opposite end to a stud 84 carried by the magazine 80, thereby urging the spool 75 in a counterclockwise direction to maintain the ribbon 55 taut.

The printing ribbon 55 is divided into a lefthand section SSL and a right-hand section 55R arranged end-toend and separated by an ink barrier 85 which may be a wax impregnanted zone extending across the ribbon 55 to prevent ink from migrating from one section, i.e., SSL, to the other, i.e., 55R. The lefthand ribbon section SSL is impregnated with ink of one color and normally,

when the machine is in its illustrated full cycle position,

the section SSL is wrapped mainly around the hub 77 which is saturated with a similarly colored ink. The right hand ribbon section 55R is impregnanted with an ink of a contrasting color and when the machine is in its full cycle position, such section 55R extends along the printing line P, as shown in FIG. 2, intermediate the hammers 42 and sectors 17. The right hand ribbon sec tion 55R is held in engagement with a hub 87 of felt or the like forming part of the spool 73 and saturated with an ink of a color similar to that contained in the ribbon section 55R.

The inking spool 73 is rotatably supported by a bracket 88 extending from the side frame 22, which bracket 88 also rotatably supports the roller 74. The spool 73 is located partly within a housing 90 also supported by the bracket 88.

The roller 72 is mounted on a ribbon slide 91, FIGS. 2 and 3, which is supported for endwise movement in guide bearings 191 formed in the side frames 21 and 22. A second slide 92 is also mounted for endwise movement in guide bearings formed in the side frames 21 and 22 and pivotally supports, at 93, a pawl 94 having an ear 95 thereon which overlies the slide 91. A spring 96 tensioned between the slide 92 and the pawl 94 normally holds the latter in its illustrated coupling position with the ear 95 located behind a shoulder 97 on slide 91.

When the machine is in its full cycle position, a spring 98 tensioned between the side frame 21 and a part of the slide 92 normally holds the latter in its lefthand home position shown in FIG. 3. The slide 91 is normally held in its lefthand position by the tension of the ribbon 55. However, during the early part of the machine cycle, and before the printing operation, the slide 92 is advanced to the right and if the pawl 94 is allowed to remain in its illustrated coupling position, the slide 91 is likewise advanced to the right to move the roller 72 to its alternate position 72a, FIG. 2. For this purpose, a cord 100, FIGS. 3,4 and 6, is attached to the slide 92 at 101 and is guided around aguide block 103 supported by the side frame 22 and onto a. pulley 104 to which it is attached at 1105. Thepulley 104 is rotatably supported at 1106 and, includes agear 1107 which meshes with gear sector 28. During theearly part of a machine cycle the sector 28 is rocked counterclockwise to, rotate the pulley 104 clockwise and thus,-

through the cord 100, normally draw the slides 91- and 92. to the right to draw the righthand ribbon section 55R over the inking spool 73 and, to draw the lefthand ribbon section 55L along the printing line P and. into a position intermediate the hammers 42.. and sectors 17 where it is held during the printing operation. During the latter half of ya machine cycle, and. after the printing operation, the cam 33 allows the slides 91 and 92 to be returned to their lefthand illustrated positions by the ribbon 55 and spring 98,- causing the right hand ribbon section 55R to again passover the reinking spool 73 and causing the lefthand section SSL to be wrapped around the reinking spool 75. Thus, the ribbon section 55R will receive a fresh charge of ink and the section 55L will likewise be recharged with ink. In: the event the ribbon 55 under the urge of spring 82 should not'be capable, of returning the slide 91, an car 160 on the slide 92 will engage the right hand end of slide 91 and thus aid the ribbon 55 in doingso.

As described in the aforementioned patents, during addition operations, the accumulator S6- is held out of mesh with the sectors 17 until after the printing operation and then the camming bailv62' is rocked counterclockwise to hold the accumulator 56 in mesh with the sectors 17 until near the end of the cycle while the sectors 17 are being returned to their home positions by the bail rod 23..I-Iowever, during subtraction, totalingand subtotaling operation, the camming bail 62 is rocked counterclockwise during the early part of the machine cycle to'hold the accumulator 56 in'meshwith the sectors 17 prior to the printing operation and while the sectors 17 are being differentially advanced. Such movement of the bail 62 is utilized to uncouple the pawl 94 from the slide.91 during such substraction, to-

taling, and subtotaling operations so that the ribbon section 55R remains intermediate the hammers 42 and the sectors 17 during the printing phase of such cycles, whereby to print subtraction factors and results of totaling and subtotaling operations in a color different from that used to print addition factors. For this purpose, the bail 62 overlies an ear 105 formed on slide 106, see also FIG. 3, which is pivotally connected at 107 to a lever 108. The latter lever 108 is pivotally supported at 110 on a bracket 111 attached to side frame 21 and has an ear 1 l2 normally underlying the pawl 94. A pin and slot connection 99 guides the lower end of the slide 106. Normally, a tension spring 113 holds the lever 108 in its illustrated counterclockwise rocked position to permit the pawl 94 to assume its coupling engagement with the slide 91. However, during a subtract, total or subtotal operation, the camming bail 62 is rocked counterclockwise prior to rightward movement of the slide 92 and therefore actuates the slide 106 and lever 108 to rock the pawl 94 clockwise to remove the car 95 of the latter from behind the shoulder 97. Accordingly, the slide 91 will not be actuated by slide 92 and the ribbon section 55R will be allowed to remain in printing position during the ensuing printing operation to thus print amounts in the second color. Later, the camming bail 62 is returned to its illustrated position allowing the spring 113 to likewise return the lever 108 so that the pawl 94 may reassume its coupling position.

DESCRIPTION OF MODIFIED FORM FIGS. 7 and 9, inclusive, illustrate a modified form of the invention wherein the printing ribbon 55a is attached at one-end120 to an inking spool 121, similar I to spool 75, and contained within a magazine 89. The

I felt hubs 150' and 151 of the spools 121 and 124, re-

spectively, are likewise impregnated with contrasting colored inks.

The spool' 124 is suitably keyed at 152 to a shaft 125,

see also FIG. 8, rotatably mounted in a bearing 126 formed in a magazine 153 which encloses the spool 124 except for an opening 154 through which the ribbon 55a passes. A gear'127 on the shaft meshes with a rack gear 128 formed on the under edge of a slide 130;

somewhat similar to slide 91 and slideably supported for endwise movement in bearings provided 175 and 176 in the side frames 21 and 22, respectively. A secondslide 131 somewhat similar to the slide 92'and driven in the samemanner, is mounted alongside slide 130 and is provided with a stud 132 overlying the righthand end of the slide 130.

A spring 129 urges the slide l3l towards its illustrated lefthand position. The slide 130 pivotally carries a pawl 940, similar in construction and function to the pawl 94 of FIG. 3, the pawl 94a normally being coupled to the slide 130 and overlying a lever 108a, similar to the lever 108. The lever 108a is pivotally connected at 135 to a slide 136, similar to slide 106 but having an ear 137 under-lying a stud 138 of a lever 140 fulcrummed at 141 and provided with an ear 142 overlying an arm 143. The latter arm 143 is fastened to a rock shaft 144 which extends across the machine. The shaft 144 is suitably pivotally supported in a manner not shown by the framework of the machine and has an arm 145 thereon underlying the depressible subtract-total control key 351. Accordingly, when the latter key 351 is depressed to initiate a subtract or total operation, the slide 136 is lowered to uncouple the pawl 94a from the slide 130. During the ensuing machine cycle, the right hand section SSaR of the ribbon 55a will be allowed to remain as illustrated in printing position and the left hand section of the ribbon 55a will remain wrapped around the inking hub 150 of the spool 121.

During operation initiated by keys other than the key 351, such as during addition operations, the pawl 94a will be allowed to remain coupled to the slide 130 and, therefore, as the slide 131 is moved to the right during the early part of the machine cycle, the rack gear 128 will rotate the gear 127 and inking spool 124 to draw the right hand section SSaR of the ribbon 55a onto the spool 124 and to draw the freshly charged left hand section SSaL of the ribbon 55a into printing position. At the end of the cycle, the slide 131 will be returned to its initial illustrated position, causing the stud 132 to likewise return the slide 130, allowing the spring 122 to wrap the lefthand section 55aL of the ribbon 55a around spool 121 and withdraw the freshly charged right hand section SSaR of the ribbon 55a into printing position under the hammers 42. g

The ribbon 55a may be readily removed for replacement or other purposes without the operator having to touch the inked portion of the ribbon 55a. For this purpose, the magazine 153 is slideably mounted on a bracket 160 extending from the side frame 22. The bearing 126 fits in a slot 161 extending lengthwise of the bracket 160 and guide prongs 162 are formed on the floor of the magazine 153 to slideably grip the top and bottom edges of the bracket 160. The magazine 89 is similarly slideably mounted on a second bracket 163 extending from the side frame 21. Guide prongs 164, similar to the prongs 162, are formed on the floor of the magazine 89 to slideably grip the top and bottom edges of the bracket 163.

In order to remove the ribbon 55a from the printer, the magazines 89 and 153 are merely grasped by the operator and slid outwardly from each other along their respective brackets 163 and 160 until the prongs 164 and 162 become detached therefrom. To replace a new ribbon 55a, this procedure is reversed.

I claim:

1. In a printing machine having a group of type elements arranged in side-by-side relation,

means for guiding a record medium past said type elements, and cyclically operable means for effecting a printing impression between said record medium and said type elements; the combination comprising an ink transferring ribbon movable lengthwise across said type elements,

said ribbon having first and second inked ribbon sections of different colors arranged in end-toend relation,

first and second ribbon inking means,

said second inked ribbon section normally extending in ink transferring relation to said type elements;

drive means controlled by said cyclically operable means prior to said printing impression to cause said ribbon to advance endwise in one direction to move said second inked ribbon section in ink receiving relation to said second ribbon inking means and to position said first inked ribbon section in ink transferring relation to said type elements,

said drive means being effective after said printing impression to cause said ribbon to advance endwise in the opposite direction to move said first inked ribbon section in ink receiving relation to said first ribbon inking means and to position said second inked ribbon section in ink transferring relation to said type elements, and

means for selectively enabling and disabling said drive means.

2. The combination according to claim 1 wherein said first and second ribbon inking means comprise ink impregnated ribbon spools engagable with respective ones of said inked ribbon sections.

3. The combination according to claim 1 wherein said first inked ribbon section is inked in a color different from the color of said second inked ribbon section.

4. The combination according to claim 1 wherein said drive means comprises a depressible key for controlling said cyclically operable means.

5. In a printing machine having a group of type elements arranged in side-by-side relation, means for guiding a record medium past said type elements, and cyclically operable means for effecting a printing impression between said record medium and said type elements;

the combination comprising a first ribbon spool having an inking hub impregnated with ink of a first color and rotatably supported on one side of said group of type elements;

a second ribbon spool having an inking hub impregnated with ink of a second color and rotatably supported on the opposite side of said group of type elements;

an ink transferring ribbon movable endwise across said type elements and attached at opposite ends to respective ones of said spools,

said ribbon having first and second ink ribbon transferring sections arranged in end-to-end relation,

first drive means operable during each cycle of said cyclically operable means for rotating said first spool prior to said printing impression to wind said first ink transferring ribbon section thereon and to present said second ink transferring ribbon section in ink transferring relation to said type elements,

second drive means for rotating said second spool after said printing impression to present said first ink transferring ribbon section in ink transferring relation to said type elements, and

means for selectively disabling said first drive means.

6. In a printing machine comprising a group of type elements arranged in side-by-side relation, means for guiding a record medium past said type elements, and cyclically operable means for effecting a printing impression between said record medium and said type elements; the combination comprising a first ribbon spool including ink absorbent material impregnated with ink of a first color; a second ribbon spool including ink absorbent material impregnated with ink of a second color; an ink transferring ribbon attached at opposite ends to respective ones of said spools and extend-' ing across said type elements, said ribbon having first and second inked ribbon sections arranged in end-to-end relation, spring means for rotating said second spool to wind said second ribbon section thereon whereby to ink said second ribbon section and to present said first ribbon section in ink transferring relation to said type elements, drive means operable by said cyclically operable means during each cycle for rotating said first spool whereby to wind said first ribbon section thereon whereby to ink said first ribbon section and to present said second ribbon section in ink transferring relation to said type elements, and means for selectively disabling said drive means. 7. In a printing machine having a group of. type elements arranged in side-by-side relation, means for guiding a record medium past said type elements, and cyclically operable means for effecting a printing impression between said record medium and said type elements; the combination comprising an ink transferring ribbon extending across said type elements, said ribbon having first and second inked ribbon sections of different colors arranged in end-to-end relation, first and second ribbon spools, each of said spools having an ink impregnated hub, means attaching opposite ends of said ribbon to respective ones of said spools, drive means operable during each cycle of said cyclically operable means for rotating said first spool to wrap said first inked ribbon section on the said hub of said first spool and to position said second inked ribbon section between said record medium and said type elements during a printing impression; means for rotating said second spool after said printing impression to wrap said second inked ribbon section on the said hub of said second spool and to position said first inked ribbon section between said record medium and said type elements, and

means for selectively disabling said drive means whereby to locate said first inked ribbon section intermediate said type elements and said record medium during a said printing impression.

8. In a printing machine having a group of type elements arranged in side-by-side relation, means for guiding a record medium past said type elements, and cyclically operable means for effecting a printing impression between said record medium and said type elements;

a frame having first and second magazine supporting guides on opposite sides of said group of type elements,

a first ribbon magazine slidably supported by said first guide for movement toward and away from said second guide,

a second ribbon magazine slidably supported by said second guide for movement toward and away from said first guide,

a first ribbon spool having a hub impregnated with an ink of a first color and rotatably supported in said first magazine;

a second ribbon spool having a hub impregnated with an ink of a second color and rotatably supported in said second magazine;

an ink transferring ribbon extending in cooperative relation to said type elements,

said ribbon having a first inked section attached to said first spool and a second inked section attached to said second spool,

said inked sections being arranged in end-to-end relation,

spring means for rotating said first spool to wind said first inked section thereon and to locate said second inked section in ink transferring relation to said type elements and to maintain said magazines on said guides,

drive means controlled by said cyclically operable means for rotating said second spool to wind said second inked section thereon and to-locate said first inked section in ink transferring relation to said type elements, and

means for selectively disabling said drive means,

said magazines being slidable in opposite directions over said guides whereby to remove said magazines and said ribbon. 

1. In a printing machine having a group of type elements arranged in side-by-side relation, means for guiding a record medium past said type elements, and cyclically operable means for effecting a printing impression between said record medium and said type elements; the combination comprising an ink transferring ribbon movable lengthwise across said type elements, said ribbon having first and second inked ribbon sections of different colors arranged in end-to-end relation, first and second ribbon inking means, said second inked ribbon section normally extending in ink transferring relation to said type elements; drive means controlled by said cyclically operable means prior to said printing impression to cause said ribbon to advance endwise in one direction to move said second inked ribbon section in ink receiving relation to said second ribbon inking means and to position said first inked ribbon section in ink transferring relation to said type elements, said drive means being effective after said printing impression to cause said ribbon to advance endwise in the opposite direction to move said first inked ribbon section in ink receiving relation to said first ribbon inking means and to position said second inked ribbon section in ink transferring relation to said type elements, and means for selectively enabling and disabling said drive means.
 2. The combination according to claim 1 wherein said first and second ribbon inking means comprise ink impregnated ribbon spools engagable with respective ones of said inked ribbon sections.
 3. The combination according to claim 1 wherein said first inked ribbon section is inked in a color different from the color of said second inked ribbon section.
 4. The combination according to claim 1 wherein said drive means comprises a depressible key for controlling said cyclically operable means.
 5. In a printing machine having a group of type elements arranged in side-by-side relation, means for guiding a record medium past said type elements, and cyclically operable means for effecting a printing impression between said record medium and said type elements; the combination comprising a first ribbon spool having an inking hub impregnated with ink of a first color and rotatably supported on one side of said group of type elements; a second ribbon spool having an inking hub impregnated with ink of a second color and rotatably supported on the opposite side of said group of type elements; an ink transferring ribbon movable endwise across said type elements and attached at opposite ends to respective ones of said spools, said ribbon having first and second ink ribbon transferring sections arranged in end-to-end relation, first drive means operable during each cycle of said cyclically operable means for rotating said first spool prior to said printing impression to wind said first ink transferring ribbon section thereon and to present said second ink transferring ribbon section in ink transferring relation to said type elements, second drive means for rotating said second spool after said printing impression to present said first ink transferring ribbon section in ink transferring relation to said type elements, and means for selectively disabling said first drive means.
 6. In a printing machine comprising a group of type elements arranged in side-by-side relation, means for guiding a record medium past said type elements, and cyclically operable means for effecting a printing impression between said record medium and said type elements; the combination comprising a first ribbon spool including ink absorbent material impregnated with ink of a first color; a second ribbon spool including ink absorbent material impregnated with ink of a second color; an ink transferring ribbon attached at opposite ends to respective ones of said spools and extending across said type elements, said ribbon having first and second inked ribbon sections arranged in end-to-end relation, spring means for rotating said second spool to wind said second ribbon section thereon whereby to ink said second ribbon section and to present said first ribbon section in ink transferring relation to said type elements, drive means operable by said cyclically operable means during each cycle for rotating said first spool whereby to wind said first ribbon section thereon whereby to ink said first ribbon section and to present said second ribbon section in ink transferring relation to said type elements, and means for selectively disabling said drive means.
 7. In a printing machine having a group of type elements arranged in side-by-side relation, means for guiding a record medium past said type elements, and cyclically operable means for effecting a printing impression between said record medium and said type elements; the combination comprising an ink transferring ribbon extending across said type elements, said ribbon having first and second inked ribbon sections of different colors arranged in end-to-end relation, first and second ribbon spools, each of said spools having an ink impregnated hub, means attaching opposite ends of said ribbon to respective ones of said spools, drive means operable during each cycle of said cyclically operable means for rotating said first spool to wrap said first inked ribbon section on the said hub of said first spool and to position said second inked ribbon section between said record medium and said type elements during a printing impression; means for rotating said second spool after said printing impression to wrap said second inked ribbon section on the said hub of said second spool and to position said first inked ribbon section between said record medium and said type elements, and means for selectively disabling said drive means whereby to locate said first inked ribbon section intermediate said type elements and said record medium during a said printing impression.
 8. In a printing machine having a group of type elements arranged in side-by-side relation, means for guiding a record medium past said type elements, and cyclically operable means for effecting a printing impression between said record medium and said type elements; a frame having first and second magazine supporting guides on opposite sides of said group of type elements, a first ribbon magazine slidably supported by said first guide for movement toward and away from said second guide, a second ribbon magazine slidably supported by said second guide for movement toward and away from said first guide, a first ribbon spool having a hub impregnated with an ink of a first color and rotatably supported in said first magazine; a second ribbon spool having a hub impregnated with an ink of a second color and rotatably supported in said second magazine; an ink transferring ribbon extending in cooperative relation to said type elements, said ribbon having a first inked section attached to said first spool and a second inked section attached to said second spool, said inked sections being arranged in end-to-end relation, spring means for rotating said first spool to wind said first inked section thereon and to locate said second inked secTion in ink transferring relation to said type elements and to maintain said magazines on said guides, drive means controlled by said cyclically operable means for rotating said second spool to wind said second inked section thereon and to locate said first inked section in ink transferring relation to said type elements, and means for selectively disabling said drive means, said magazines being slidable in opposite directions over said guides whereby to remove said magazines and said ribbon. 